If your hard drive is 'constantly ticking', it suggests that something is continually trying to access the drive (either to read or to write data).
Press Ctrl, Alt and Delete simultaneously. Click on the 'Processes' tab. Look down the 'CPU' column. The only process which should normally have double figures alongside it is 'System Idle Process'. Everything else should normally show '00' or a very low number. If there's anything with an unexpectedly large number, post here to tell us what it is.
Then look at the 'Mem Usage' column. Anything showing over 20,000K should normally be regarded as suspect (except any big program which you know should be running, such as your internet browser). Again, post here with the details of any suspect processes.
It's also possible that your laptop has insufficient RAM. If it can't access enough RAM it uses 'virtual memory' instead. That means that it temporarily stores data on your hard drive which really belongs in RAM, thus slowing everything down.
Chris